Recent research on self-recognition in human infants suggests that the ability to recognize one's own image emerges during the first two years of life and that the study of self-recognition might provide important information regarding the origins of the sense of self. There are serious methodological problems, however, in previous studies of self-recognition in infancy. The most serious problem is the failure of previous studies to compare the infant's response to his own mirror image with his response to another infant's image. Without this critical comparison it is difficult to infer whether a specific behavior is indicative of self-recognition. The purpose of the proposed study is to determine, (1) the specific behaviors which indicate self-recognition, (2) the age at which these behaviors emerge and (3) whether the contingency of the infant's image is a relevant factor in the infant's response. The behavioral responses of 48 infants in 4 age groups (12-14 month, l5 -l7 month, 18-20 month, 21-23 month) to the presentation of a televised image of (1) themselves in the present (T.V. mirror image), (2) themselves in the past (T.V. movie of self) and (3) another infant (T.V. movie of other infant) will be examined in terms of (1) specific types of behavior thought to be indicative of self-recognition in infants and (2) the stage of self-recognition displayed. Comparisons across conditions will reveal which behaviors are displayed specifically in response to the infant's own image, whether the contingency of the image is an important factor and whether the infant is capable of differentiating his own image in the present vs. the past. The results could have important implications for our understanding of the origins of the sense of self in infancy and may have potential application for the study of childhood psychopathology.